Information systems (IS) researchers have developed a substantial base of theoretical and empirical research for investigating phenomena associated with information technology (IT) infrastructure and IS implementation. The majority of prior studies have focused on perceptions of IS use, usefulness, support, and similar organizational and human aspects of implementation; however, recent empi- rical results suggest the importance of technical issues in IS implementation. As a first step toward providing more empirical research on the impact of technological issues in IS implementation, this paper reports on the development and test of a model that captures the dimensions of technological changes in IT infrastructure. Using a survey of 302 individuals who recently participated in a software upgrade, evidence is provided on the content validity, construct validity, and reliability of an instrument measuring four dimensions of perceived technological change in IS implementation: functionality, user interface, technical quality, and external compa- tibility. In addition, a sample application of the new model is provided which shows that technological changes in IT infrastructure affect user acceptance of information technology.